A register file (RF) is an array of registers, e.g., memory cells, in a central processing unit (CPU). The register file can be positioned between an instruction-generation portion of the CPU and an instruction-execution portion of the CPU to temporarily store operands, e.g., instructions and memory locations. Because of the role of the register file, an erroneous transfer of data from the register file can result in the CPU executing incorrect instructions or can result in the CPU writing data to unintended memory locations.
The registers in the CPU are typically random access memory (RAM) cells. Register files are generally used as low level caches, due to fast read and write operates as compared to last level caches. The registers include write ports and read ports through which data may be written to and read from individual registers, respectively.
Conventional techniques are provided that attempt to reduce erroneous operation of register files and related circuitry. For example, to ensure that various transistors in the related circuitry operate correctly and transfer signals adequately, manufacturers provide a guardband for CPU supply voltages, e.g., Vdd or Vcc, on a chip. However, guardband use in supply voltages decreases the energy efficiency.